p5.js入门教程之平滑过渡(Easing)

function setup() {  
 createCanvas(400, 400); 
  
}  
 
function draw() { 
 background(220); 
 ellipse(mouseX,mouseY,20,20); 
} 

var x=0; 
var y=0; 
var targetX=0; 
var targetY=0; 
var easing=0.1; 
function setup() {  
 createCanvas(400, 400); 
 x=mouseX; 
 y=mouseY; 
}  
 
function draw() { 
 background(220); 
 targetX=mouseX; 
 targetY=mouseY; 
 x+=(targetX-x)*easing; 
 y+=(targetY-y)*easing; 
 ellipse(x,y,20,20); 
} 

var rectX=0; 
var rectY=0; 
var rectHeight=100*0.618; 
var rectWidth=100; 
var hoverR=255; 
var hoverG=128; 
var hoverB=128 
var exitR=255; 
var exitG=255; 
var exitB=255; 
var R=0; 
var G=0; 
var B=0; 
var ease=0.1; 
 
function setup() {  
 createCanvas(400, 400); 
 rectX=width/2; 
 rectY=height/2; 
 R=exitR; 
 G=exitG; 
 B=exitB; 
}  
 
function draw() {  
 background(220); 
 if(mouseX>=rectX-rectWidth/2 && mouseX<=rectX+rectWidth/2&& 
   mouseY>=rectY-rectHeight/2 && mouseY<=rectY+rectHeight/2){ 
  R+=(hoverR-R)*ease; 
  G+=(hoverG-G)*ease; 
  B+=(hoverB-B)*ease; 
 }else{ 
  R+=(exitR-R)*ease; 
  G+=(exitG-G)*ease; 
  B+=(exitB-B)*ease; 
 } 
 fill(R,G,B); 
 rectMode(CENTER); 
 rect(rectX,rectY,rectWidth,rectHeight,8); 
}